Content by Patrick Wagner
Should I Spray for Soybean Aphids? What’s the Threshold?
Although many soybean fields are behind schedule, so are the soybean aphid populations. In many reported areas, there are hotspots within a field where a few soybean plants may be heavily infested.
Lady Beetles of South Dakota
A guide for monitoring, properly identify, and promoting the growth of lady beetles.
An identification guide to Native Pollinator Plants of South Dakota for Managed Landscapes
A guide of Native Pollinator Plants in South Dakota.
Green Cloverworms Causing Defoliation in Soybean
Populations of green cloverworm, a caterpillar pest of soybean, have been increasing over the last couple of weeks in South Dakota. Although green cloverworm caterpillars feed on soybean leaves, defoliation rarely results in economic loss. However, reports of increasing populations of green cloverworm and increasing amounts of defoliation suggests that scouting for this insect pest is warranted.
Checkerspot Caterpillars in Sunflower
While scouting sunflower near Sturgis this week, we came across outbreak levels of checkerspot caterpillars that were defoliating the plants. Similar sightings have been reported throughout Western and Central South Dakota in recent weeks.
Horse Flies and Deer Flies Becoming Abundant
The above-average precipitation this year has led to increased numbers of horse flies and deer flies across South Dakota. Widespread flooding and an overall abundance of available water has made conditions perfect for these flies.
Small Populations of Soybean Aphids Observed in South Dakota
While scouting fields last week, we observed small populations of soybean aphids near Volga, South Dakota. Although no sustained populations were observed, it is a good reminder that soybean aphid scouting should occur throughout the growing season to prevent population outbreaks.
Watch for True Armyworms in Wheat
This week we observed some true armyworm caterpillars in winter wheat fields. The caterpillars were still relatively small, which means they will continue feeding for some time. So far, the true armyworm caterpillars were still feeding on the leaves of the nearly mature wheat, but they have the potential to also clip heads off of the plants.
Bean Leaf Beetles Are Back: Adults Observed Near Beresford
Earlier this year, we observed a large emergence of overwintering bean leaf beetles throughout much of the state. We are again observing quite a few bean leaf beetles beginning to emerge. These emerging beetles are the result of overwintering beetles mating and laying eggs.
A Case of Mistaken Caterpillar Identity
Tweets about European corn borer (Ostrinia nubilalis) caterpillars in the stems of conventional corn and feeding in the whorls of corn are crossing my Twitter feed. Unfortunately, there is a problem with some of these tweets. Not all of the caterpillars that are being identified as European corn borer caterpillars are actually European corn borer caterpillars!